#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
using namespace std;

class A 
{
public:
	A(int b=100)
	{
		_b = b;
	}
private:
	int _b;
};
class date
{
public:
	date(int year = 2023, int month = 3, int day = 23)
	{
		_year = year;
		_month = month;
		_day = day;
	}
private:
	int _year;
	int _month;
	int _day;
	A _aa;
};
int main()
{
	cout << "hello world" << endl;
	date d(2003,10,20);
	date d1(d);
	return 0;
}